1. Field of the Invention
This invention relates generally to surgical apparatus and more specifically to an improved catheter for use in performing liver surgery.
2. Definitions
The following terms, as used herein, shall have the following meanings:
"distal" refers to the end of a hepatic bypass catheter that is inserted into a patient.
"proximal" means the end of the hepatic bypass catheter that remains outside the patient.
"caudal" means that portion of the inferior vena cava below the junction of the hepatic veins and vena cava.
"cephalad" means that portion of the inferior vena cava above the junction of the hepatic veins and vena cava.
3. Discussion of the Prior Art
In the case of traumatic injury resulting in liver hemorrhage, chances of survival are slim due to current lack of ability to achieve zero blood pressure in the liver; a prerequisite to the surgical repair at the site of bleeding. In two recent studies of hepatic injury, (C. E. Lucus et al. "Prospective Evaluation of Hemostatic Techniques for Liver Injuries, " J. Trauma 1976;16:442-451 and D. V. Feliciano et al., "Management of 1000 Consecutive Cases of Hepatic Trauma (1979-1984) Ann Surg 1986; 204:439-445) only about ten percent of the patients required a major procedure for control of hemorrhage. In each study, blunt trauma was the most lethal, knife wounds least lethal, and gunshot wounds intermediate. In the last category, shotgun wounds were the most severe and approached blunt trauma in terms of morbidity and mortality. Most of those who succumb to their liver injuries, do so in the operating room. Three out of four hepatic injuries, regardless of cause, can be managed with simple measures such as laparotomy alone or in combination with suture or drainage.
Fabian and Stone (T. C. Fabian and H. H. Stone "Arrest of Severe Liver Hemorrhage by an Omental Pack." South Med J 1980; 73:1487-1490) reported a series of 113 cases of "massive liver injury". secondary to blunt trauma and treated with omental packing with a surprisingly low mortality of only eight percent. Feliciano et al. (D. V. Feliciano et al. "Intrabdominal Packing for Control of Hepatic Hemorrhage: A Reappraisal " J. Trauma 1981; 21:285-290) reported a small series of ten patients with extensive liver injury and hemorrhage unresponsive to standard techniques for control that were treated by intra-abdominal packing about the liver. The packs were removed either by re-operation or through drain sites and only one patient died.
To establish zero blood pressure in the liver to facilitate clotting and control hemorrhage, it is desirable to occlude the hepatic artery, the portal vein and the hepatic veins. Unfortunately, the retro hepatic inferior vena cava and hepatic veins are difficult to adequately expose for vascular control. Atrial-caval shunting is a useful technique along with the Pringle maneuver (temporary occlusion of the porta hepatis or portal vein, proper hepatic artery and common bile duct with a vascular clamp, Penrose drain, or thumb and forefinger). The latter procedure accomplishes hepatic inflow occlusion.
Atrial-caval shunting along with inflow occlusion has been used by Kudsk et al (K. A. Kudsk et al. "Atrial-Caval Shunting (ACS) After Trauma " J. Trauma 1984; 25:833-837) to treat eighteen patients with massive hemorrhage from the inferior vena cava, the hepatic veins or the liver with an operative mortality of 72%.
A number of devices for atrial-caval shunting have been described. They can be inserted by way of the right atrium or the right common femoral vein. The right atrial technique requires a right thoracotomy, or an extension of the mid-line laparotomy to a median sternotomy to expose the heart and isolate the supradiaphragmatic inferior vena cava with an umbilical tape. A large purse string suture is placed in the right atrium. An atriotomy is made and a large bore chest tube fenestrated proximally, inserted and clamped. The right atrial purse string suture is tied after the tube has been passed successfully beyond the hepatic and renal veins as determined by palpation from chest and abdominal exposures. The inferior vena cava is then encircled above the renal veins with an umbilical tape and the vena cava ligated about the tube above and below the injured segment. This technique isolates the suprarenal infradiaphragmatic inferior vena cava and arrests hemorrhage from the hepatic veins or vena cava without interfering with cardiac return. Because this technique requires manipulation of the heart, arrhythmia potentiated by acidosis and hypothermia may result.
Testas et al (American Journal of Surgery 133 pp. 692-696, Jun., 1977) describe a hepatic bypass catheter useful for vascular exclusion of the liver. Testas et al used a silastic triple lumen catheter containing two separately inflatable balloons near on end. The catheter was introduced into 35 dogs by means of the femoral vein. The correct positioning was controlled by a large medical incision, then vascular exclusion of the liver was performed by successfully inflating the caudal (proximal) balloon, clamping the hepatic pedical and finally inflating the upper (cephalad) balloon. While the investigators observed coagulation in the catheter, pretreatment of the catheter with heparin prevented such coagulation in further studies.